• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2017.11a
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• pp.41-43
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• 2017

본 논문에서는 IoS (Internet of Signage) 환경에서 실감형 데이터 전송을 위한 상황 인지 기반 적응형 전송기법을 적용하고 이를 분석한다. 사이니지 네트워크 환경에서는 임의적인 다중 경로 페이딩, 간섭 등과 같은 왜곡 요소가 존재할 수 있기 때문에 이를 대처하기 위해 무선 송신기에서는 채널 환경에 대한 인지 이후, 그에 따른 MCS (Modulation and Coding Scheme)를 선정 및 안테나 기법을 선정한다. MCS 및 안테나 기법 선정을 위해 무선 송신기에서는 사전에 알고 있는 통계적인 SNR (Signal-to-Noise Ratio) 값을 통해 문턱값을 계산하고, 수신 사이니지로부터 얻은 CSI (Channel State Information)와의 크기 비교를 한다. 시뮬레이션 결과에서는 상황 인지를 기반으로 매 순간 최적의 전송률을 달성할 수 있음을 볼 수 있다.

• Proceedings of the Korea Contents Association Conference
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• 2004.05a
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• pp.291-295
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• 2004

Recently, distributing information on the Internet is common in our daily li(e. Also, data exchange on Internet has rapidly changed the way we connect with other people. But current firewall and IDS(Intrusion Detection System) of the network level suffers from many vulnerabilities in internal computing informations and resources. In this paper, we analyzes Traceback System that based on active network and design of Traceback System that based on active network for efficiently traceback.

• 한국IT서비스학회:학술대회논문집
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• 2009.05a
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• pp.361-364
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• 2009

침입의 방법이 점차 치밀해지고 다양해짐에 따라 새로운 방식의 침입 탐지 기법 역시 지속적으로 요구되어진다. 기존의 오용 탐지 방법론은 탐지율은 뛰어나지만 새로운 침입형태에 대한 대응 능력이 부족하다. 이러한 단점을 보완하고자 등장한 것이 비정상 행위 탐지 방법론이다. 하지만 현재까지의 연구는 네트워크나 서버 OS, 데이터베이스 등 각 개별 분야에 대해서만 진행되고 있어 그 탐지 능력에 한계가 있다. 본 논문에서는 이러한 한계를 극복하고자 사용자의 네트워크 및 운영체제 로그를 통합 하고, 데이터마이닝 기법 중 빈발 패턴 마이닝 기법을 이용한 보다 정확한 비정상 행위 탐지 기술을 제안한다.

• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
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• 2003.12a
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• pp.538-542
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• 2003

본 논문에서는 액티브 네트워크 상에서 강력한 자원 관리와 액티브 응용의 제어를 위해 접근제어 메커니즘을 적용한 안전한 리눅스 커널을 분석 설계하였다. 설계된 접근제어 모델은 직무기반 접근제어를 이용하여 권한을 효과적으로 통제하고, 신분 및 규칙 기반 접근제어를 이용하여 정보 및 시스템의 비밀성, 무결성, 가용성의 보장 및 시스템의 불법적인 접근을 방지할 수 있다. 리눅스 마이크로 커널 기반 접근제어 모델을 직무, 보안등급, 무결성 등급 및 소유권의 다단계 보안 정책을 기반으로 시스템의 불법적인 접근, 직무기반, 소유권 등의 다단계 보안 정책을 기반으로 하여 시스템의 불법적인 접근을 통제 할 수 있다.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.4
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• pp.252-258
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• 2013

As WSN is energy constraint so energy efficiency of nodes is important. Because avoiding long distance communication, clustering operating in rounds is an efficient algorithm for prolonging the lifetime of WSN and its performance depends on duration of a round. A short round time leads to frequent re-clustering while a long round time increases energy consume of cluster heads more. So existing clustering schemes determine proper round time, based on the parameters of initial WSN. But it is not appropriate to apply the round time according to initial value throughout the whole network time because WSN is very dynamic networks nodes can be added or vanished. In this paper we propose a new algorithm which calculates the round time relying on the alive node number to adapt the dynamic WSN. Simulation results validate the proposed algorithm has better performance in terms of energy consumption of nodes and loss rate of data.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.12
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• pp.2372-2380
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• 2015

In this paper, we propose frequency allocation and path selection scheme in underlay cognitive radio (CR) networks using network coding. In the proposed scheme, we choose the path with consideration of network coding and interference temperature in underlay CR networks and propose an optimization problem to maximize the system throughput of secondary users (SUs). Then, we represent the proposed optimization problem as the multi-dimensional multiple-choice knapsack problem and give the theoretical upper bound for the system throughput of SUs by using linear programming. Finally, we compute the system throughput of SUs by using brute-force search (BFS) and link quality first (LQF) scheme in underlay CR networks. Simulation results show that the system throughput of SUs with BFS is higher than that with LQF in underlay CR networks with and without application of network coding, respectively.

• Journal of Distribution Research
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• v.11 no.3
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• pp.55-78
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• 2006

In business-to-business setting, dyadic relationships between firms are of paramount interest. Recent developments in business practice strongly suggest that to understand these business relationships, greater attention must be directed to the embedded context within which dyadic business relationships take place. As a result, it is important to develop an understanding which is to move from dyadic business relationship to business networks. The purpose of the current study is (1) to identify types of network benefits: information acquisition, access to tangible resources, cooperative support from network members, (2) to model network benefit efforts on a customer orientation for customer firm, (3) to examine the relationship between network characteristics and network benefits. Adopting resource-based view and social capital theory, the conceptual model is proposed. In order to develop and test a model, this paper was empirically to examine how network characteristics can reinforce network benefits leading to focal firm's customer orientation using 123 firms. Through structural equation modeling, this research found that (1) density influences information acquisition, access to tangible resources, cooperative support from network members, (2) centrality increases information acquisition, access to tangible resources. We also find that information acquisition, access to tangible resources, cooperative support from network members enhances focal firm's customer orientation. Finally, We discuss several theoretical and practical implications, and suggest limitations for the research and future research issue.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.10B
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• pp.621-629
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• 2007

In cognitive radio (CR) network, the channels are generally classified into either the unavailable channels that are occupied by incumbent users or the available channels that are not occupied. The conventional channel classification scheme may result in poor utilization of spectrum holes since it does not take the spatial relationship between CR node and incumbent users into consideration. In this paper, we propose an efficient channel management scheme for the centralized CR network to maximize the spectrum holes by overcoming the shortcomings of conventional scheme. In addition, we mathematically analyze the effectiveness of proposed scheme. Based on the proposed channel management scheme, we also propose the rendezvous algorithm, which can establish the control channels between base station and CR node under the dynamically changing spectrum environment.

• The Journal of the Korea Contents Association
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• v.17 no.6
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• pp.153-168
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• 2017

Existing researches on movie genre have been focusing on the relationship between a specific genre and performance of a movie. However, most of films cross into multiple genres and new approach is needed for analyzing a genre network. In this study social network analysis was used to analyze the genre centrality and its relationship with movie performance by developing a genre network, i.e. network among multiple genres constructed via genre co-occurrence pattern in a specific movie. Three index of genre centrality, eigenvector centrality, degree centrality, and bonacich power centrality, were tested for the valued genre network. Results showed that the relationship between genre centrality and movie performance appeared to be inverted U-shaped. This empirical finding is in line with the theory of ambidexterity which emphasizes the balance of exploration and exploitation. In addition, this study can provide practical implications for movie producers, distributors, and theaters that need to develop genre strategies.

• Journal of Korea Multimedia Society
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• v.11 no.7
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• pp.986-996
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• 2008

The home network environment based on the power line communication has some unexpected events. The noise source from the home appliances makes the network impedance increased, and the transmission packets distorted. Therefore the packet transmission from the source node may not be delivered to the destination node directly. In this paper we propose a new self-healing mechanism which relays the packet to the directly unreachable destination automatically with the help of intermediate nodes. In order to choose the minimum required intermediate nodes our mechanism makes a spanning tree with both the directly reachable nodes and indirectly reachable nodes via the intermedia nodes. We developed the network simulator in order to compare its performance to the Echelon's repeater selecting mechanism. Though it required more packet relations than Echelon's but the reachable probability to the destination was highly increased about two times.